Welcome to my Tips and Tweaks guide to Microsoft Flight Simulator X with SP2. This is a compilation of various ideas, tips, configuration changes, and tweaks which may (or may not!) improve your experience with FSX. Like its predecessors, FSX is very demanding of your hardware. Unfortunately, we virtual pilots are very demanding of our simulators! This creates a bit of a problem because as of this writing, no single desktop hardware platform can run FSX at its most lush settings at a reasonably acceptable degree of smoothness.
With the introduction of Service Pack 1 (SP1) in May 2007, and Acceleration/SP2 in XXX 2008, FSX has become much more manageable for many users. The list of fixes and performance improvements is lengthy, but needless to say your FIRST tweak for FSX should be to obtain and install SP1 and SP2, or purchase and install the Acceleration add-on pack.
(If you buy Acceleration, it contains SP1 and SP2 in it – you do not need to install either of them individually)
This document may help you tweak you FSX install on your existing hardware to try to get the best presentation possible. FSX is such a rich and capable platform, it would be a shame to purchase the simulation only to cast it aside in frustration from performance.
For the sake of any personal examples, my relevant PC specs at the time of writing were... AMD Athlon 64 x2 3800+, 2 GB of reasonably generic RAM, and an nVidia 7900GT 256 MB card.
If you installed FSX to the C: drive, the fsx.cfg file is located in
This location is the same for all installations, including the Steam Edition.
What to Expect from Tweaking
The art of tweaking depends entirely upon your expectations for performance. Some folks are more interested in great image quality, and less interested in smoothness – others are solely focused on smoothness at the expense of visual detail... most of us fall somewhere in between – interested in trading off some visuals for some performance to achieve a happy medium.
When tweaking FSX, patience is a key. There doesn’t seem to be a single magic bullet that will cure all your ills – when we jumped from FS2004 to FSX, we gained huge improvements to the visual systems which provide major improvements to the visual world. Unfortunately, these huge changes cost a lot when it comes to processor time. Yes, the ACES development team spent hundreds of hours on optimizing the simulation engine and visual system, but even the most expert of optimization cannot make up for sheer processing power – and that’s what FSX is ready to use down the road.
Any way you slice it, the fact this document exists is a testament to those intrepid explorers who went out, experienced FSX, and found ways to help improve the experience for everyone else.
Quick Note on FSX Service Packs and Expansion Packs
Service Pack 2 was released concurrently with the Acceleration add-on pack. Because SP2 is included in the Acceleration add-on, users who have purchased Acceleration will also have all SP2 items.
FSX In-Game Settings
Understanding and properly setting the in-game system sliders is the foundation for nearly all tips and tricks for FSX performance. With that in mind, I thought it best to briefly go over some of the performance-related settings and sliders with their capabilities.
Target Frame Rate:
The target frame rate is thought of as the FPS lock. FSX does much more than just display pretty pictures on the screen – it needs to calculate your location, weather effects, system states, and a slew of other items in order to determine what to show on the screen. If you set the Target Frame Rate slider to an appropriate setting, you can give the sim the breathing room it needs for all the other calculations before it gets to rendering graphics. By locking at a reasonable rate, you also take steps to prevent wild FPS fluctuations, such as going from high detail to low detail areas when flying.
Important Notes – Does the FPS Lock cause more harm than good? Some users have indicated that when they lock their FPS, stuttering and *lower* than expected framerates seem to creep in. When they unlock their rates, smooth flying returns along with higher rates. I experimented with this, and found there is some truth to it. Your mileage may vary, of course.
Filtering: (Bilinear, Trilinear, Anisotropic)
The filtering selection sets up what texture filtering mode will be used by your video system. Bilinear is nice, Trilinear is usually better, and Aniso proves best – One word of caution, though. Users have experienced slowdowns when selecting Aniso, so perhaps it’s best to use Bi- or Tri-.
Most users are finding best performance is gained by setting this at Bi or Tri, and using your video card’s drivers to "force"-adjust the Anisotropic settings.
This turns the sim-driven antialiasing mode on and off. It is often recommended to turn AA (OFF) in this location, and use your video card driver settings to turn AA on. This will give you more control over which AA mode to use, and may result in both better image quality and frame rates.
Note on Filtering and Anti-Aliasing: It is recommended that you set your video card drivers to "Application Controlled" for AA and AS, and use FSX’s in-game settings to turn the features on and off. This is opposite what was ideal for FS2004, but most users are finding superior performance with in-game control over these graphic quality items rather than in-driver.
Note on Filtering and Anti-Aliasing:
It is recommended that you set your video card drivers to "Application Controlled" for AA and AS, and use FSX’s in-game settings to turn the features on and off. This is opposite what was ideal for FS2004, but most users are finding superior performance with in-game control over these graphic quality items rather than in-driver.
Global Texture Resolution: (Very Low / Low / Medium / High / Very High)
Your preferred setting may very, but I tend to keep this at High or better. Very High allows for the largest possible texture sizes, stepping downward cuts back into smaller textures helping to free video memory and texture swapping resources, benefiting performance. This setting matches the custom texture resize process that some tweakers are using, but it does it without actually resizing.
Lens Flare: (On/Off)
Turns the lens flare effect on and off. This imposes a slight performance hit, and sometimes is considered a nuisance (as you usually don’t get lens flare when looking out the window of a real airplane). From my experience, this poses only a small performance impact and is a pleasing effect, so it remains on.
Light Bloom: (On/Off)
Turns the blooming effect on and off. Light bloom is a new feature with FSX and displays a dynamic halo around bright lights and bright reflections. Bloom looks gorgeous, but imposes a high performance penalty – especially with mid-to-low end graphics cards. Bloom requires the graphics system to draw the screen image twice, hence the slowdown. Faster video cards may yield better results. I fly with bloom off, but I may sacrifice some AA or AS settings on the video driver settings to see if I can make it workable.
Advanced Animations: (On/Off)
I fly with this on, but haven’t compared performance with it off to know if there is any difference.
DX10 Preview Mode: (On/Off) (SP2 and Vista with DX10 capable hardware only)
Turns the DX10 preview mode on and off. Most people recommend keeping this off, as it has a tendency to break add-on airplanes. DX10 preview is a sneak peek into some things that MSFS can do in the future, but it fell short of some individuals performance expectations. Microsoft included it for you to check out, however you might experience some hiccups and problems along the way.
High Resolution 3D virtual cockpits: (On/Off)
This probably adjusts the detail level of the VC textures. I’ve left mine on, but haven’t done a comparison with it off. I tend to fly in the 2D cockpits more, so VC hasn’t garnered much attention from me. If you are an exclusive 2D pilot, you may be inclined to move this to off to potentially save some resources. If you are an exclusive 3D pilot, you will be best served turning this on.
2D Panel Transparency: (0-100%)
This allows you to see through a 2D panel. A neat feature if you fly in high console cockpits in the 2D mode. I haven’t seen any performance impact with it off or at any on setting.
Aircraft Casts Shadows On Ground: (On/Off)
I always leave this on – if flying in spot view and attempting a landing, the shadow gives vital altitude information that I can’t sacrifice.
Aircraft Casts Shadows on Self: (On/Off)
New for FSX, aircraft can now shadow themselves! I haven’t turned this option on, so I cannot speak to it’s impact.
Aircraft Landing Lights Illuminate Ground: (On/Off)
Just as the text reads – I turn this on for an air of realism. I’ve never tested performance with it turned off.
Level of Detail Radius: (Small/Medium/Large)
This slider adjusts how far out detailed textures extend from the airplane. Smaller values use a smaller ring, larger values use a larger ring.
Mesh Complexity: (0-100%)
This determines the amount of detail used when rendering terrain (hills and mountains). A higher figure will use the better detail available, a lower figure will "smooth out" some of the samples in order to reduce processor loads. If you fly low and slow in mountainous areas, you may wish to keep this setting high to retain the grandeur of valley flying. If you primarily fly in flat areas, reducing this setting may lower the workload the sim has to do for you. Some users do report good gains in performance by bringing this setting lower.
This setting restricts the maximum level of detail the terrain engine would try to display if the above Mesh Complexity setting was at 100%. Mesh resolution varies from stock to vendor supplied, so pick the detail level appropriate for your flying needs. The more detailed the mesh, the more performance impact it may have. I believe FSX ships with at best 38M mesh, and that would be a good starting setting. If you have higher detail 3rd party mesh, be certain to adjust your resolution to match the best available resolution of your addon. (I haven’t seen anything better than 10m as of 2008)
Like the above Mesh Resolution setting, this setting controls the best possible texture resolution. You can customize the setting here – move it to 4m to provide you with FS2004-era textures (and save some processing power), or move it to 1m for FSX-supplied stock textures. The more detailed settings in the centimeter range will have no effect right now, but they will be used down the road should an addon vendor release scenery using VERY high resolution images.
Shader Model 3 in effect here! Water details and reflectivity are controlled with this setting. Users are reporting they get the best performance with the OFF-High 1 setting. Moving into the 2x settings requires more video processing power, and many users report slower performance at those settings.
This controls the amount of scenery objects your system will display in detailed cities and around airports. The higher the slider, the more objects are displayed. This does have a bearing on performance, especially near high-detail airports. For best performance, keep this slider low, in the Normal area. Ultra-fast processors may be able to work at a higher level.
Like the Scenery Complexity setting, this slider controls the amount of Autogen scenery in the world. High settings have an EXTREME impact on performance, so it is advised that you keep Autogen turned low. This isn’t all that bad, because FSX has introduced a much higher density of Autogen overall – FS2004’s "High" setting is comparable to FSX’s "Sparse" setting! Users have also reported that due to FSX’s improved stock textures, Autogen isn’t as needed to give a good illusion of flight. They turn Autogen off, and fly "barren", but they reap in the benefits of not having to draw Autogen objects.
Ground Scenery Shadows: (On/Off)
As the checkmark says, it causes ground objects to cast a shadow. This is another option I leave off, but your preference may vary. Untested performance impact.
Special Effects Detail:
How much detail is in water spray, waves, dust from a grass landing? This slider determines it. I haven’t tested it’s performance impact, but I run mine at Medium. Your preference may vary.
Cloud Draw Distance:
Clouds have a significant performance impact on the simulator – especially detailed clouds (see below). By adjusting the distance they are drawn in, you can adjust your system’s performance. I usually notch this one click above the lowest (70mi?), but some users may prefer to have this higher.
Thermal Visualization: (None/Natural/One Other)
Depending on your flight location, turning off thermal visualizations may improve your performance. This would be bad if you fly gliders, however since most of us don’t glide on a regular basis, this may be best to keep off. Users report a 3.0 to 0.5 FPS improvement with the settings change.
Cloud Detail (Simple/Detailed)
Simple clouds will bring you back to the old FS2002 days with 2D looking clouds. Detailed clouds are equivalent to FS2004-style detailed clouds which have a volumetric look and feel. Moving to simple clouds will give you a major performance improvement, however it does impact the look of the simulator in a fairly large way. If you are experiencing bad performance under heavy weather, you may wish to look into this setting. In later tips and tricks you may see that it’s possible to change out the cloud textures which may help cloud rendering.
Cloud Coverage Density (Only available with detailed clouds)
Detailed clouds can be adjusted in density. The more dense they are, the more cloud "objects" are used when rendering the skies. Obviously, the higher the slider, the worse the performance. I usually keep this slider higher than the midpoint because I appreciate the cloudy skies. In later tips and tricks you may see that it’s possible to change out the cloud textures which may help cloud rendering.
Airline Traffic Density
General Aviation Density
Airport Vehicle Density
Ships and Ferries
As you probably imagined, the traffic density sliders adjust how many objects are up in the skies, on the ground, or in the water as you fly. Each one could have a major or minor impact on your performance. Airplane traffic still imposes a performance hit, although most users haven’t commented as to whether it is a greater hit than in FS2004. (This leads me to believe it’s less than or equal to the FS2004 hit). ROAD traffic is the new problem! While adding a significant realism option with cars and trucks moving on the highways, all those little 3D objects in motion hit your processor like a ton of bricks. Unless you can cut back on other settings to make up for it, it is recommended that you scale back your road traffic to regain CPU cycles. Page
FSX Community Tips and Tricks
And now for the fun! This section goes over the various changes and settings alterations that can be made to FSX in order to further customize your simulator experience. Keep in mind that you should always always back up any files or settings you are changing here, in the event that something goes horribly wrong. Additionally, because this is a static document, some of these tips and tricks may have updated information not in this document – I’ve included the original thread or source link so that you can check for updates.
Service Pack Installation
Credit To: ACES Team, AVSIM members. The flightsim community has had great success with the SP1/SP2 and Acceleration service releases. It is strongly recommended that you install all available updates to FSX before flying. SP2 is also the benchmark release for developers – many newer addons and airplanes may be written against SP2 and require it for proper use.
Autogen Performance - Editing the Default.xml File
Credit To: Many in the FS2004 days, along with Matt Fox & Richard Ludow Back in the FS2004 days, it was found that there was a problem with the "custom" Autogen used in the simulator. All those chicken restaurants, gas stations, power substations, etc. etc. were draining resources. The fix was to remove or rename the (fs2004)Autogendefault.xml, thus disabling this type of Autogen object. The actual bug was fixed in the 9.1 patch, but many users chose to keep this file renamed or removed because of the performance benefit it imposed. Fast forward to today – FSX’s default.xml file contains many entries, many of which are now "standard". Removing this file is not recommended anymore due to the severe impact it may have on your autogen scenery. Editing it is another story though... Check on various flightsim websites for edited default.xml files. Some were done by Matt Fox, and AVSIM user "Rhumbafloppy" in the early days of FSX, and may still be available today.
Autogen Performance - Customizing Autogen Densities
Credit To: Paul (ACES) Adding two lines to your FSX.CFG file in the [Terrain] section allows you to customize the density and balance of autogen objects. The following lines are the "default" values that populate the variables when the lines are not in the config file. Increasing the number will increase the number of objects of a type, decreasing the number will lessen the count. This config change works in conjunction with the Autogen slider – for example, if you decrease the numbers below, the max slider setting will display less than originally designed, and the sparse slider setting will display less than originally designed.
[Terrain] TERRAIN_MAX_AUTOGEN_TREES_PER_CELL=4500 TERRAIN_MAX_AUTOGEN_BUILDINGS_PER_CELL=3000
(Max possible for either = 6000)
Keep in mind that you probably shouldn’t use this tweak to lower BOTH values unless you find that the lowest slider isn’t low enough. Best use of these config lines would be to shift the balance of the two Autogen object types to your liking. Some users may want Autogen trees only, so they would lower buildings to zero. Others may want mostly buildings and very few trees, so they would lower trees to say, 500. I’d recommend NOT using the settings below as a substitute for the Autogen slider – this may lead to confusion down the road if you forget that you have adjusted the config file, and can’t understand why your Autogen slider is giving you so few objects... just a thought!
Various threads are indicating a sweet spot of 3000 and 1500 respectively as being worthwhile settings to try for improvements...
Texture Performance - Autogen Tree Texture Replacements
Credit To: Mike Kelly, Aimé Leclercq Mike took the time to cut the Autogen tree bitmaps in half, thus halving the video memory needed to generate Autogen. From there, Aimé took it one step further and decided to entirely rework the textures for both EULA compliance as well as improving the stock textures. This resulted in Aimé’s TreeX package. (Currently on V.2) TreeX is a great freeware utility which will automatically replace your autogen tree textures with some that are both beautiful, and efficient – and in three different texture sizes for performance tuning. TreeX is a great extension to have, and can indeed help the texture footprint of the autogen trees. There are other, additional tree texture packs now in existence. You may wish to research and find the best option for you.
You can download TreeX here:
Texture Performance - Cloud Texture Replacements
Credit To: Mike Kelly, and FS2004 experience SP1 Impact: This tweak will assist the system by lowering the memory footprint of cloud textures. Its impact may not be as great in the post-SP1 world, but it is still worth considering. As above AND as it was in FS2004, Mike applied the texture reduction idea to the FSX cloud textures. FSX uses aggressively sized textures for clouds in order to bring you a vivid flying experience. Unfortunately, the textures may be a little too big for some systems. Visit the above link to find the adjusted files. Your mileage may vary, but generally this tweak will further reduce the video memory footprint used by textures, and this may assist with frame rates and/or blurries. The file in the thread may be considered a violation of the EULA, so look to the thread for information on how to do this yourself should it have been removed. In addition, certain payware offerings now exist such as Flight Environment X which can provide you with lower-resolution cloud textures. Be certain to explore!
Texture Performance - Pops and Stutters During Panning
Credit To: Brian (ACES)
If you're getting stutters or "pops" during turns or when pan your view around, try adding this to your fsx.cfg file:
This line will go in the [BufferPools] section – if it isn’t there, you may have to create it. The default pool size is 1,000,000 but sometimes (If a lot of things are drawing like autogen) that isn't enough. Increasing it to 5 or even 10 million trades off some of your video memory against having to re-allocate these things all the time.
The buffer pool is (apparently) the amount of memory used by the system to quickly reintroduce textures. You can scale this setting to your liking – perhaps halving the amount suggested by Brian (2500000) in order to balance memory needs.
Blurries – How to Balance Blurries with Framerates
SINGLE CORE MACHINES ONLY – NOT EFFECTIVE ON MULTICORE MACHINES
Credit To: Adam (ACES) REQUIRED READING – Read the thread AND the knowledgebase articles above. They give pertinent and worthwhile information on the topic. Take your time, as they have important concepts which need to be understood before moving onto tackle blurries.
Blurries – no single word evokes more exhausted emotion in the Flight Sim community than blurries. (Except perhaps your least favorite add on developer, but we’ll leave that to another guide). Blurries are a fact of life in MSFS due to the way the on-screen graphics are drawn. Simply put, blurries occur when the simulator doesn’t have enough processor time to process and draw the outdoor textures, and has to spend it’s time working on other aspects of the simulation like "where am I" and "where is the AI traffic", etc. etc. Adam wrote a very good guide to blurries, why they exist, and what can be done to customize things – see the above link. Rather than detail the tweak here, I’ll leave that to the above link, both at AVSIM and to the MS Knowledgebase. The fact that Microsoft has placed an article about this in the knowledgebase is evidence enough that the blurries issue is both important and known to the MS engineers, so for now, we have to deal with the MSFS architecture provided to us. In short, you will need to add this line on your single core machine:
...to your FSX.cfg file in the [MAIN] section. The higher this fractional number goes, the more time is dedicated to the terrain/texture engine. If you go too high, you’ll get FPS problems – too low, and you’ll get blurry problems. In essence, it’s a manual slider to help you balance how much time the ground textures get. 0.33 is the default setting.
Users in the forums are indicating that they have brought the setting down to as low as 0.10 with little ill effects, but I would imagine blurries would creep in at those settings. Your mileage, as always, may vary!
Blurries - Texture Bandwidth Tweak
Credit To: A great many folks from back in the FS2004 days Back in the FS2004 days, blurry textures were the biggest complaint from users. Flying low and fast would quickly muddy textures and cause a generally poor experience. One of the first fixes to come out was adjusting the bandwidth the sim uses for texture loading. This is accomplished with a config file line change. In your FSX.cfg file, there will be a line:
If you RAISE this number, you will give more bandwidth to the textures. This may lead to less blurries, but it also may introduce microstutters and little hiccups which could upset an otherwise smooth sim experience. I do not know what the "default" value is, but mine was set at 30. I typically bounce this number up by a factor of x3. I have yet to see any adverse effects, but at the same time I haven’t seen any *observable* benefits. (I tend to make tweaks in one lump, so I’m never certain which tweak is helping the most). Some users in the FS2004 days have set this as high as 400, but users today are mentioning that high settings to this number are imposing FPS hits. This tweak may work in conjunction to Adam’s (ACES) fiber tweak above.
Aesthetics – Narrower Power Line Easements
Credit To: Alex (ACES) via Email One of the landscape items that JUMPED out at me in FSX was the power line easements. I am not sure if it is the textures that they selected for them, or the width, or what – but they seem to be far more visually jarring than they used to be. In my own personal opinion, at least in the fall FSX season in New England, the power line easements are just a little too prominent, and I felt it was the width. You can edit this, however! A quick email to ACES and the "problem" was solved. You will have to edit your terrain.cfg file (located in the root of FSX) As always, BACK UP YOUR ORIGINAL before you go playing!
// Misc vector types - utility [Texture.201]
And in that section, replace the value on this line...
...figure with a size of your choosing. I went half, down to 20, and things look better! You should also change the same line in this section...
// Misc vector types - utility [Texture.202]
...with the same figure. Both config sections should be back-to-back in the terrain.cfg file. Note that there are other settings in this file and texture possibilities, but I haven’t yet become bold enough to see what they do.
Hardware Performance – AGP Aperture Size
For AGP Card Users Only
It has been reported that adjusting your AGP aperture size may be of benefit to you AGP vid card users. The de-facto standard for FS2004 was an aperture of 64 MB. Users who HAVE a 64 MB setting who have changed to 128 or 256 have noted much better texture loading speeds and sharpness. This is likely due to the increased texture size for FSX terrain, and the larger aparture size better handling the textures. Changing your AGP Aperture size is only done in your computer's BIOS, and should only be done if you are comfortable entering the BIOS. (You could reeeeally mess up your computer if you go hamming around in there). Chances are, though, if you have an AGP card and you set up a 64 MB aperture, you'll know how to get back in and change it once more.
Easy to use software for boosting FSX Performance
You can now purchase a FSX performance booster program created by developer FSPS. For more information on this product, with immediate download after purchase, please click here.